|Publication number||US7422673 B2|
|Application number||US 10/443,303|
|Publication date||Sep 9, 2008|
|Filing date||May 22, 2003|
|Priority date||May 22, 2003|
|Also published as||EP1486589A1, US7897021, US8083919, US20040231992, US20070039825, US20090000945|
|Publication number||10443303, 443303, US 7422673 B2, US 7422673B2, US-B2-7422673, US7422673 B2, US7422673B2|
|Inventors||H. Frederick Hess, Jr., H. Frederick Hess, III, Steven Jovanovic, James E. Rittel, Jr.|
|Original Assignee||Ufs Corporation|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (16), Non-Patent Citations (3), Classifications (16), Legal Events (2)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present invention relates to membrane electrode cells and systems used in electrodeposition coating. More particularly, in certain embodiments, the present invention relates to advantageous membrane electrode cell assemblies having electrode enclosures wherein the membrane seal of the enclosure is provided by a compression-independent, bonded arrangement.
As further background, electrodeposition coating, or “electrocoating”, is broadly classified into two categories. Anionic electrodeposition uses anionic paints; cationic electrodeposition uses cationic paints. Both of these processes are in current commercial use.
Membrane electrode cells are commonly used in electrodeposition systems. Such cells act as opposing electrodes in the electrodeposition process, with the object being painted serving as the counter-electrode. Membrane electrode cells also serve in many systems to remove ions from the paint bath to maintain proper paint bath chemistry.
The membrane electrode cell can have many shapes, and often is shaped as a flat rectangle, arcuate or semi-circle, tube or cylinder. Electrodeposition processes employing such membrane electrode cells are disclosed for example in U.S. Pat. Nos. 4,851,102, 4,711,709 and 4,834,861.
The membrane used in a membrane electrode cell can be either ion-exchange or neutral. The membrane is arranged in such a fashion as to separate the electrocoating paint bath from the electrode. An electrolyte fluid flows between the inside of the membrane and the outside of the electrode. This electrolyte fluid, which is often comprised mostly of deionized water and a small amount of acid or amine (depending on the type of electrocoating employed), is responsible for flushing the ions that pass through the membrane into the membrane electrode cell from the paint bath. The conductivity of this electrolyte fluid usually is maintained in the range of 500 to 2,000 microSiemens/cm (microMho/cm).
To separate the electrode from the paint bath, it is a common practice to provide a seal between the membrane and other structural member(s) of the electrode cell. These seals have in the past commonly been achieved by mechanical elements such as bolted flanges, which form a pressure-dependent seal between the flange, membrane, and an outer rim or periphery of an electrode housing. These seals can be difficult to maintain, and present complications in repair and replacement operations.
In light of this and other background in the field, there remain needs for membrane electrode assemblies of simplified design and which are more readily repaired, replaced and/or maintained. The present invention is addressed to these needs.
Accordingly, one aspect of the present invention provides a system for electrodeposition of paint on a counter-electrode. The inventive system includes an electrodeposition chamber containing an electroconductive liquid medium including paint. At least one membrane electrode assembly is in the chamber in contact with the liquid medium. The electrode assembly includes an electrode and an enclosure separating the electrode from the liquid medium. The enclosure has a first structural member and a membrane bonded to the first structural member to provide a seal therebetween. A counter-electrode upon which paint is to be electrodeposited is in the chamber in contact with the liquid medium. Passage of electrical current between the counter-electrode and the electrode in the membrane electrode assembly through the liquid medium causes electrodeposition of the paint on the counter-electrode. In preferred embodiments, the electrode within the membrane electrode assembly is a flat or arcuate-shaped electrode, and the membrane can be bonded to the first structural member by welding, chemical bonding agents, polymers, and the like.
In another embodiment, the present invention provides a membrane electrode assembly for use in a paint electrodeposition chamber containing a liquid medium. The assembly includes an electrode, and an enclosure for separating the electrode from the liquid medium. The enclosure includes a first structural member, and a membrane bonded to the first structural member to provide a seal therebetween. In certain embodiments, the electrode is a flat or arcuate shaped electrode, and the membrane is bonded to a multiple-sided periphery of the structural member.
In another embodiment, the present invention provides a membrane electrode assembly for use in a paint electrodeposition chamber, wherein the assembly includes an electrode, and an enclosure for separating the electrode from a liquid medium within the chamber. The enclosure includes a non-electrically-conductive coating covering a first surface portion of the electrode. The enclosure further includes a membrane for separating a second surface portion of the electrode from the liquid medium.
In still another embodiment, the invention provides a membrane electrode assembly for use in a paint electrodeposition chamber, wherein the chamber has an electrode mount adjacent to the top of the chamber. The membrane electrode assembly of the invention includes an electrode and an enclosure for separating the electrode from the liquid medium in the chamber. The enclosure also includes a membrane, and a frame holding the membrane, the frame having a top end and a bottom end. An attachment member is located adjacent the top of the frame, for attaching the membrane electrode assembly to the electrode mount. The membrane electrode assembly includes a bumper element for contacting a wall of the electrodeposition chamber, the bumper element attached to the frame and spaced from the top end of the frame. In the inventive arrangement, the attachment member, frame and bumper element are arranged to force the bumper element against the wall when the attachment member is attached to the electrode mount.
In still another embodiment, the present invention provides a membrane electrode assembly for use in a paint electrodeposition chamber containing a liquid medium. The membrane electrode assembly includes a tubular electrode, and a tubular enclosure including a membrane for separating the electrode from the liquid medium. The tubular electrode received within said tubular enclosure wherein liquid can be trapped within the interior of the tubular electrode. A valve is provided in fluid communication with the interior of the tubular electrode and adapted to selectively permit fluid flow from the interior of the tubular electrode into the tubular enclosure. Electrodeposition systems and methods using such assemblies also form a part of the present invention.
Additional features, advantages and embodiments of the invention will be apparent to those of ordinary skill in the art from the descriptions herein.
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to certain preferred embodiments thereof and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations, further modifications and applications of the principles of the invention as described herein being contemplated as would normally occur to one skilled in the art to which the invention relates.
As disclosed above, the present invention provides membrane electrode assemblies, electrodeposition systems, and related methods for electrodepositing paint on a counter-electrode.
In general, membrane electrode assemblies of the invention, and used in systems and methods of the invention, will include an electrode, and an enclosure for separating the electrode from liquid medium in the electrodeposition chamber. The enclosure will typically include at least one membrane, such as a selectively permeable membrane, e.g. an ion-exchange membrane. The enclosure will include at least one other element, typically a frame member, and a seal between the membrane and the frame member to complete the enclosure. In accordance with the preferred embodiments of the invention, this seal is provided by a bonding of the membrane to the frame member. This bonding may be achieved, for example, by welding, chemical bonding agents, and the like. Such bonded seals are in general compression-independent, meaning that they do not require compression of the membrane against the frame member in order to achieve a seal, as is the case in many current systems in which a flange is tightened over the membrane in order to seal it against a frame member.
With reference now to
With reference now to
With reference now to
With reference now to
With reference to
With reference now particularly to
With reference now to
With reference now to
Referring now to
With reference to
Membrane electrode cell 80 also includes a tubular electrode 89 disposed within the membrane shell. Electrode 89 will serve as an anode, or cathode, depending upon the type of electradeposition painting to be undertaken, as would be understood by those skilled in the art. Electrode 89 will typically be made of metal or another suitable conductive material. A preferred material is stainless steel. An electrolyte inlet tube 90 extends into the membrane shell and through the interior of the tubular electrode 89, ultimately terminating in an internal electrode cap 91. In use, electrolyte fluid is passed through tube 90 and exits the bottom of cap 91 thereafter flowing upwardly in the membrane shell between the outer surface of electrode 89 and the inner surface of membrane 86 and its accompanying cloth layers. In accordance with one aspect of the invention, a valve 94, especially a one-way valve, is provided in fluid association with the electrolyte supply tube 90, and adapted to allow fluid flow into supply tube 90, and to resist fluid flow out of electrolyte tube 90. Illustratively, this may be provided by the inclusion of a three-way or “T” connector 92 situated within the electrolyte supply tube 90, having affixed within its horizontally-extending leg a section of PVC or other tubing 93. One-way valve 94 is trapped at the shoulder of the connection of tube 93 and “T” connector 92. In this regard,
With continued reference to
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US3620955 *||May 16, 1969||Nov 16, 1971||Carrier Engineering Co Ltd||Cathode cell|
|US3945900||Sep 23, 1974||Mar 23, 1976||Dorr-Oliver Incorporated||Electro ultrafiltration process and apparatus|
|US3959111||Aug 14, 1974||May 25, 1976||Le Nickel||Electrolytic cell|
|US4075069||Mar 22, 1976||Feb 21, 1978||Mitsui Mining & Smelting Co., Ltd.||Processes for preventing the generation of a mist of electrolyte and for recovering generated gases in electrowinning metal recovery, and electrodes for use in said processes|
|US4201653||Jul 27, 1978||May 6, 1980||Inco Limited||Electrowinning cell with bagged anode|
|US4212337||Mar 31, 1978||Jul 15, 1980||Union Carbide Corporation||Closure fastening device|
|US4363345||Nov 18, 1981||Dec 14, 1982||Union Carbide Corporation||Reclosable container|
|US4515674||Aug 3, 1982||May 7, 1985||Toyota Jidosha Kabushiki Kaisha||Electrode for cationic electrodeposition coating|
|US4663016||Sep 3, 1985||May 5, 1987||Toyota Jidosha Kabushiki Kaisha||Apparatus for electrodeposition coating|
|US4834861 *||Nov 23, 1987||May 30, 1989||Poly Techs Inc.||Membrane electrode for electrodeposition coating|
|US4879013||Jul 19, 1988||Nov 7, 1989||Ppg Industries, Inc.||Method of cationic electrodeposition using dissolution resistant anodes|
|US4933051||Jul 24, 1989||Jun 12, 1990||Omi International Corporation||Cyanide-free copper plating process|
|US5078850||Mar 27, 1990||Jan 7, 1992||Polytechs Inc.||Electrodeposition coating system|
|US5507929||Jul 21, 1994||Apr 16, 1996||Koch Membrane Systems, Inc.||Submergible electrode apparatus for dialysis|
|US5591316 *||Jun 5, 1995||Jan 7, 1997||Ufs Corporation||Electrocoat painting method using guarded tubular membrane electrode cells|
|US5759371||Jul 9, 1996||Jun 2, 1998||Ufs Corporation||Electrocoat painting overload protection circuit and method|
|1||Alcore Fabricating Corporation, "High Performance HP-C Semi-Circular Anolyte Cells for Electro-Coating Systems," Product Information Nov. 25, 1992.|
|2||Arelco, "Electro D Alyss Cells Products Book", no date available.|
|3||UFS Corporation Product Data Sheet, TECTRON SD Side Membrane Electrode Cell, Oct. 29, 1999.|
|U.S. Classification||204/626, 204/640, 204/282|
|International Classification||C25D17/10, B01D61/46, B01D61/52, C25D17/12, C25D13/22|
|Cooperative Classification||C25D13/22, C25D17/12, B01D61/46, B01D61/52|
|European Classification||B01D61/52, C25D17/12, C25D13/22, B01D61/46|
|Sep 2, 2004||AS||Assignment|
Owner name: UFS CORPORATION, INDIANA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HESS, JR., H. FREDERICK;JOVANOVIC, STEVEN;RITTEL, JR., JAMES E.;AND OTHERS;REEL/FRAME:015111/0985;SIGNING DATES FROM 20040601 TO 20040825
|Feb 27, 2012||FPAY||Fee payment|
Year of fee payment: 4